JPH07316517A - Electron ray curing release agent composition - Google Patents

Abstract

PURPOSE:To obtain an electron ray-readily curable release agent composition, containing respective specific organopolysiloxanes, capable of providing a cured film, hardly causing the migration and changing with time, having a stable peel strength in the initial period and stably peelable by light peeling and useful as a back treating agent for the tacky tapes. CONSTITUTION:This composition comprises (A) 100 pts.wt. organopolysiloxane, expressed by formula I {R<1> is a (un)substituted monovalent hydrocarbon; R<2> is H or methyl; (m) is 1-8; (a) and (b) are each a positive number and [(a)+(b)] <=3} and having 100-3000cP viscosity at 25 deg.C and 1.412-1.428 refractive index and (B) 1-20 pts.wt. organopolysiloxane, expressed by formula II [R<3> is a 1-18C monovalent hydrocarbon, OH or an alkoxy; (n) is a positive number] and having 100-1000000cP viscosity at 25 deg.C and <=1.410 or 1.430 refractive index.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is useful as an electron beam curable release agent composition, especially as a backing agent for adhesive tapes and as a release paper coating material for adhesive labels, since the cured film exhibits releasability. The present invention relates to an electron beam curable release agent composition.

[0002]

2. Description of the Related Art Various types of electron beam curable release agents have been proposed, but most of them have a radical-reactive functional group introduced into the siloxane main chain. It is believed that these silicone compositions undergo a reaction due to radicals generated by electron beam irradiation and cure proceeds, but this cure proceeds through a radical reaction,
Since this curing is completed in a very short time, high productivity can be expected for this.

Therefore, this electron beam-curable release agent is used as a surface treatment agent for various substrates. Since this release agent has a property of easily releasing an adhesive substance, the adhesive tape has a back surface treatment. It is used as an adhesive and a release agent for adhesive labels.

[0004]

However, when this electron beam curable silicone is used as a release agent for release paper, the electron beam curability becomes higher as the content of radical functional groups in the organopolysiloxane increases. However, since the radical functional group itself has a strong polarity, the interfacial tension and hardness of the coating film increase with an increase in the radical functional group, and thus there is a problem that the peeling property with respect to the adhesive substance deteriorates. This also has a drawback in that the peeling force is small at the initial stage, but increases with time while the adhesive substance is stuck. for that reason,
In this regard, an electron beam curable release agent composition having a stable peeling force even in the initial stage and showing little change over time has been earnestly desired.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an electron beam curable release agent composition which solves the above disadvantages and problems, and it is represented by the formula (A) (1).

[Chemical 2] (Wherein R ¹ is the same or different, unsubstituted or substituted 1
Valent hydrocarbon group, R ² is a hydrogen atom or a methyl group, and m is 1
-8, a and b are positive numbers and are represented by a + b≤3), 100 parts by weight of organopolysiloxane having a viscosity of 100 to 3,000 cp at 25 ° C and a refractive index of 1.412 to 1.428, (B) formula (2) _{^{R 3 3 SiO- [R 1 2}} SiO] n -SiR 3 3 ········ (2) ( here R ¹ is as defined above, R ³ is a monovalent hydrocarbon having 1 to 18 carbon atoms Group, a hydroxyl group or an alkoxy group, n is a positive number), and 1 to 20 parts by weight of organopolysiloxane having a viscosity at 25 ° C. of 100 to 1,000,000 cp and a refractive index of 1.410 or less or 1.430 or more. To do.

That is, the inventors of the present invention have conducted various studies to develop an electron beam curable release agent composition in which the peeling force is stable in the initial stage and changes little over time, and as a result, an acrylic group-containing organic group was identified. When the organopolysiloxane represented by the formula (1) is used as the component (A) and the organopolysiloxane represented by the formula (2) as the component (B) is blended, the initial peeling force is Is stable, and when this composition is applied to a substrate and it is irradiated with an electron beam, it cures well, and this is because the component (B) is not completely compatible with the component (A). In addition, although the component (B) bleeds out in the cured film and a light peeling phenomenon appears here, it was found that the peeling force does not change even with time, and this is why Electrons with excellent physical properties required Verify that become curable release composition and completed the present invention. This will be described in more detail below.

[0007]

The electron beam curable release agent composition of the present invention is represented by the formula (2) and the component (A) consisting of the organopolysiloxane having an acrylic group-containing organic group represented by the formula (1). The composition of the present invention obtained by mixing the component (A) and the component (B) has a stable peeling force in the initial stage. This is coated on a substrate and cured by irradiation with an electron beam, which exhibits a light peeling property, but since this does not change the peeling force over time, it has excellent physical properties. It becomes a curable release agent composition.

The organopolysiloxane as the component (A) constituting the electron beam curable release agent composition of the present invention has the above-mentioned formula (1).

[Chemical 3] R ¹ is an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, an alkenyl group such as a vinyl group or an allyl group, an aryl group such as a phenyl group or a tolyl group, or a carbon atom of these groups. The same or different unsubstituted or substituted monovalent selected from chloromethyl group, trifluoropropyl group, cyanoethyl group, etc., in which some or all of the hydrogen atoms bonded to the atoms are replaced with halogen atoms or cyano groups, etc. Hydrocarbon group, R ² is a hydrogen atom or a methyl group, m is 1 to 8, a and b are positive numbers, and a + b ≦
It is 3.

The organopolysiloxane is as follows:

[Chemical 4]

[Chemical 5] What is shown by is illustrated.

This product has a viscosity of 100 at 25 ° C.
3,000 cp, which has a refractive index of
If it is less than 1.412, the curability by electron beam is reduced, and if it is greater than 1.428, the curability by electron beam is improved, but the surface properties of the coating after curing are degraded, so that the refractive index is 1.412 to 1.428. However, it may be a single siloxane or a mixture of a plurality of organosiloxanes having different degrees of polymerization and different functional groups.

Further, the organopolysiloxane as the component (B) constituting the electron beam curable release agent composition of the present invention has the above formula (2) R ³ ₃ SiO- [R ¹ ₂ SiO] _n -SiR ³ ₃ ... (2), R ¹ is the same as described above, and R ³ is a monovalent hydrocarbon group of 1 to 18 carbon atoms of the same kind as R ¹ , a hydroxyl group or an alkoxy group, n Is assumed to be a positive number, and the following is exemplified.

[Chemical 6]

This product has a viscosity of 100 to 1, at 25 ° C.
It should be 000,000 cp, which has a refractive index of
If the refractive index of 1.410 <(B) <1.430, then this (B)
Since the component is completely compatible with the component (A) and the desired characteristics cannot be obtained, this refractive index is 1.410 or less, or
Must be 1.430 or above.

The mixing ratio of the component (A) and the component (B) is such that (A) / (B) = 100/20 or more, and if the amount of the component (B) is too large, the curability due to electron beam irradiation decreases. However, if the component (B) is too small such that (A) / (B) = 100/1 or less, the desired effect cannot be obtained because the bleed-out cannot be performed properly on the surface.
It is preferable that (B) = 100/1 to 100/20.
In this composition, if necessary, an oxygen curing inhibition control agent such as diethylamine ethanol or piperidine,
A reaction diluent, an organic solvent, a leveling agent, a filler, an antistatic agent, an antifoaming agent, a pigment, an organopolysiloxane and the like may be added.

The electron beam curable release agent composition of the present invention is used by coating it on a base material, and the base material includes polyester, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, polyimide and the like. Paper base materials such as plastic films, sheets, glassine paper, kraft paper, and clay-coated paper obtained from the synthetic resin of, and laminated paper such as polyethylene laminated paper and polyethylene laminated kraft paper are used.

The composition of the present invention may be applied to these substrates by a known method such as roll coating, gravure coating, wire doctor coating, air knife coating and dipping coating. If this coating amount is too small, coating unevenness occurs on the substrate and the peeling force becomes unstable, and if it is too large, it causes poor electron beam transmittance and curing failure. This may be about 0.01 to 20.0 g / m ² .

Further, since the electron beam curable release agent composition of the present invention is cured by electron beam irradiation, an electron beam irradiation device is required for its use, which is a curtain system, a scan system or A double scan method may be used. If the accelerating voltage of the electron beam due to this electron beam irradiation is less than 100 KV, the amount of energy transmission will be insufficient,
If it exceeds 00KV, it will not be economical, so this is 100KV ~
It should be in the range of 1,000 KV. If the electron beam irradiation dose is less than 0.5 Mrad, curing failure will occur.
The above is not preferable because the base material deteriorates, so 0.5 to 10.0
It should be in the range of Mrad.

[0017]

[Examples] Examples and comparative examples of the present invention will be given below. The parts in the examples are parts by weight, and the viscosity is the value measured at 25 ° C. Shows the measured value by the following test method. [Curability] An electron beam curable release agent composition was applied onto polyethylene laminated paper at 1.0 g / m ² and an accelerating voltage of 165 was applied using an electron beam irradiator C-150 (trade name, manufactured by ESI).
The electron beam dose (Mrad) required to form a completely cured film when irradiated with an electron beam and cured at KV is shown. However, this judgment of curing was made at the time when the coated surface was not fogged by rubbing with a finger.

[Releasability] An electron beam curable release agent composition
It was coated on polyethylene laminated paper at 1.0 g / m ² and an accelerating voltage of 165 was applied using an electron beam irradiator C-150 (described above).
After curing by irradiating electron beam with KV, acrylic resin solvent-based adhesive Olivine BPS-8170 is applied to the cured film surface.
After applying [Toyo Ink Co., Ltd. product name] and heat-treating at 100 ° C for 3 minutes, a high-quality paper with a basis weight of 64 g / cm ² is attached to the treated surface, aged at 25 ° C for 20 hours, and aged Cut the sample of 5cm width and 180 ° using a tensile tester.
The force required to peel pull the lamination sheet at an angle at a peeling speed of 300 mm / min (g / 5 cm) by measuring this value as the initial peel strength, the lamination conditions 20 g / cm ² at 70 ° C. The time-dependent peeling force was measured after pressure-bonding for 3 days with the load.

[Residual Adhesion Ratio] A cured film of an organopolysiloxane composition is formed on a polyethylene laminated paper in the same manner as in the case of releasability, and a polyester tape / lumirror 31B [a product manufactured by Nitto Denko Corporation] [Name] was attached, a load of 20 g / cm ² was applied, heat treatment was performed at 70 ° C. for 20 hours, and then the tape was peeled off and attached to a stainless plate. Next, the force (g / 2.5cm) required to peel off this treated tape from the stainless steel plate was measured, and the percentage of the force required to peel off this untreated standard tape was taken as the residual adhesion rate. .

Examples 1 to 7 and Comparative Examples 1 to 3 Formulas in which the component (A) has a viscosity of 800 cp and a refractive index of 1.414.

[Chemical 7] The organopolysiloxane I represented by the formula (1) is prepared, and the component (B) has a viscosity of 100, 500, 5,000 or 100,000 cp and a refractive index of 1.403.

[Chemical 8] Organopolysiloxane II with a viscosity of 3,000 cp
With an index of 1.404

[Chemical 9] Organopolysiloxane III with a viscosity of 5,000
An expression with a refractive index of 1.381 at cp

[Chemical 10] Organopolysiloxane IV with a viscosity of 3,000 cp
With refractive index 1.423

[Chemical 11] An organopolysiloxane V represented by

Then, the organopolysiloxane I and the organopolysiloxanes II to V were blended in the blending ratio shown in Table 1 to obtain 10 kinds of electron beam curable release agent compositions having the viscosity and the refractive index shown in Table 1. Was prepared and coated on polyethylene laminated paper so that the coating amount was 1.0 g / m ^2, and then this was irradiated with an electron beam from an electron beam irradiator C-150 (described above) to cure it. The curability, releasability in the initial stage and aging, and the residual adhesion rate (remaining contact) of this product were examined, and the results shown in Table 1 were obtained.

[0022]

[Table 1]

[0023]

The present invention relates to an electron beam curable release agent composition, which comprises the organopolysiloxane represented by the formula (1) as the component (A) and the formula (1) as the component (B). It is characterized by being composed of an organopolysiloxane shown in 2), but this is easily cured by irradiation with an electron beam of about 3 Mrad. Since the force is also stable and does not change with time, it has an advantage that a cured film having a stable peeling force can be obtained by light peeling.

Claims (1)

[Claims] 1. A formula (A): (Wherein R ¹ is the same or different, unsubstituted or substituted 1
Valent hydrocarbon group, R ² is a hydrogen atom or a methyl group, and m is 1
~ 8, a, b are positive numbers a + b≤3), and the organopolysiloxane has a viscosity at 25 ° C of 100 to 3,000 cp and a refractive index of 1.412 to 1.428.
100 parts by weight, (B) Formula R ³ ₃ SiO- [R ¹ ₂ SiO] _n -SiR ³ ₃ (wherein R ¹ is the same as above, R ³ is a monovalent hydrocarbon group having 1 to 18 carbon atoms, a hydroxyl group Or an alkoxy group, n is a positive number), and 1 to 20 parts by weight of an organopolysiloxane having a viscosity at 25 ° C. of 100 to 1,000,000 cp and a refractive index of 1.410 or less or 1.430 or more. An electron beam curable release agent composition.